A few years ago, a very good friend of mine suffered a stroke from a dissected carotid artery. Once they had an image of her neck and saw the damaged blood vessel, one of the first questions the attending neurologist asked was, "Has she been to a chiropractor recently?" In fact, every single neurologist who saw her in subsequent weeks asked the same question.
These questions reflect a belief among some doctors that neck manipulation by chiropractors can cause damage to the arteries in the neck, leading to the creation of clots that can then enter the brain and cause an ischemic stroke. Here is an example of an article on the subject.
As you know, I am not a doctor, and I do not pretend to be an expert on such things. I also know that chiropractors do miracles for many people and alleviate lots of pain. So this is not a diatribe against that profession. Far from it.
Obviously, this is an area in which clinical trials and randomized studies are difficult. But, I now always warn my friends to be alert to this potential danger and seek gentle approaches to neck pain.